Conventionally, molecular design is performed by using a molecular simulation. A problem of the molecular simulation is mainly the calculation amount, and a means has been provided to effectively process the calculation amount at higher speed.
For example, an electric charge determination method or the like is provided in a basis function, which is continuous for at least more than second order derivative, is applied. In the electric charge determination method, when either one grid point (or a particle) in a pair of grid points (or a pair of particles) is overlapped with a grid point in a roughly level grid which is at one level higher than the current level, an electric charge is determined for a grid point of a higher level so that an energy value of a pair in the higher level always corresponds to a proper energy value of the pair in the current level.
In drug development using a computer (computational drug development), calculation time and calculation resources cost less than a laboratory experiment. Therefore, computational drug development is simply used to comprehend a microscopic phenomenon which is not acquired by the laboratory experiment. If attempting to acquire data which are in no way inferior to the experiment, five days may be spent with approximately 320 Central. Processing Units (CPUs) for one reagent.    Patent Document 1 JP2007-80044A